doberman vwd

[blackcat]

can someone please explain Doberman Vwd for me. I understand what the desease is and I understrand what recessive genes are and everything but I don't understand what it would mean if parents where to be carriers of the disease. would that mean that the puppies would get sick from it? Or would that just mean they would be carriers?

 

[MafiaPrincess]

You have clear, carrier and affected dogs. Clear 2 normal genes, carrier 1 normal 1 affected, and Affected.. 2 mutated genes..

Breed 2 dogs that have it and you'll have an entire litter with it.
Breed 2 dogs carrying it, you'd have 25% affected, 50% carrying, 25% clear.
Breed a carrier to a clear dog, 50 carrying, and 50% clear.

 

[blackcat]

Okay now what does it mean if the dog has it? Does that mean that he/she is going to bleed everywhere? Or does that mean that if I beed two dogs with it they will be bleeders?

 

[MafiaPrincess]

Affected means they lack the VWd protein and have a bleeding disorder.
Carrying it they don't have the disorder, but they have half the mutated genes to pass on that will create the disorder if bred to a dog either carrying or affected.

 

[blackcat]

So should one avoid puppies that have been bred carrier to carrier?

 

[MafiaPrincess]

If it was me.. I'd avoid. Everything I've read says vwd status alone shouldn't make or break ones breeding decisions.. as onyl a small percentage, maybe 15% of the dobe population is vwd clear..

But.. I'd want to find a carrier x normal mating if possible.. as 25% of the puppies in that hypothetical mating would have vwd. And some may not show clinical signs of it.. what if you got a pup that did..

Cockers can have a different form of it.. it's still not testable though. Think I'd be tryign to avoid full blown vwd if I could.

 

[OutlineACDs]

If a breeder is willing to do a carrierXcarrier breeding, they should be responsible enough to have ALL pups tested before they go to their new homes.

 

[Murreydobe]

Okay now what does it mean if the dog has it? Does that mean that he/she is going to bleed everywhere? Or does that mean that if I beed two dogs with it they will be bleeders?

There's a big difference between a doberman that's genetically affected and one that's actually clinically affected. VERY few genetically affected dobermans actually ever have any kind of clotting difficulty. Most lead perfectly normal lives, endure injuries and surgeries with no problems whatsoever.

This is because the mutation that causes vWD in dobes is considered a "leaky" gene. That means affected dogs make a percentage (up to 20%) of von Willebrands Factor, just not a normal amount. The vWF they do produce usually provides enough clotting ability in most situations.

If vWD becomes a problem it's usually as a secondary complication to something far more serious. But again, that's pretty rare.

 

[Murreydobe]

If a breeder is willing to do a carrierXcarrier breeding, they should be responsible enough to have ALL pups tested before they go to their new homes.

I do agree with this..buyers should have the option of deciding whether they want to buy an affected dog or not.

And LOTS of carrier x carrier breeding is done in dobermans. This is because when the dna test was first marketed there were very few clear dogs. Restricting breeding to clear x clear or even clear x carrier would narrow the genepool down to dangerous levels.

Instead, geneticists suggested that breeders take a few generations to improve their vWD status. There definitely are more clear dogs around now than ever before, although we're still not at the point where carrier x carrier breeding can be abandoned. Someday....

 

[Murreydobe]

Breed 2 dogs that have it and you'll have an entire litter with it.
Breed 2 dogs carrying it, you'd have 25% affected, 50% carrying, 25% clear.
Breed a carrier to a clear dog, 50 carrying, and 50% clear.

This isn't quite right.

In a carrier x carrier breeding each puppy has a 25% chance of being affected, a 50% chance of being a carrier, a 25% chance of being clear.

Clear x carrier-50% chance for each puppy to be carrier, 50% for each to be clear.

But these are just estimates, and frequently don't play out that way in real life. I know of more than one carrier x carrier breeding where every puppy was clear, others where all the pups were carriers.

 

[MafiaPrincess]

Tooly much. You repeated EXACTLY what I said for percentages, yet told me I was wrong. That needs a round of applause...

 

[Dekka]

No mafia is right. That is how Mendelian genetics work. Punnett squares are the best way of figuring our potential genotypes when you are looking at simple genetic traits (nothing polygenetic, etc)

For a dog to get sick with it they have to inherit both genes I believe (not conversant on this particular disease) If you breed 2 carriers then the chance is as good they would have the disease as would that they would be completely clear.

 

[Murreydobe]

Tooly much. You repeated EXACTLY what I said for percentages, yet told me I was wrong. That needs a round of applause...

Yes, you *were* wrong, and obviously still don't understand where you were in error. For example, you said:

"Breed 2 dogs carrying it, you'd have 25% affected, 50% carrying, 25% clear."

These estimates are for EACH puppy, not for distribution within the litter. There's a difference.

 

[Dekka]

Yes, you *were* wrong, and obviously still don't understand where you were in error. For example, you said:

"Breed 2 dogs carrying it, you'd have 25% affected, 50% carrying, 25% clear."

These estimates are for EACH puppy, not for distribution within the litter. There's a difference.

Now you are wrong. That is the statistical likely hood of each puppy and the 'theoretical yield' of the litter.

 

[CanadianK9]

Mp, and dekka, this is what I call a "Slinky Alert!"

 

[Murreydobe]

Now you are wrong. That is the statistical likely hood of each puppy and the 'theoretical yield' of the litter.

Okay, I stand corrected, my apologies.

But I'll still say the chances of the "theoretical load" of each litter being exact is extremely slim, since breedings don't produce 1000 puppies in a litter..in real life, genetics just aren't that..tidy.

You can count on the fact that a clear dog can never produce an affected puppy, and an affected dog can never produce a clear. When it comes to using carriers for breeding, you're at the mercy of the roll of the genetic dice..anything could happen. You could have all clears, you could have all carriers, you could have all affecteds..or you could have any combination of the three categories.

 

[Dekka]

Okay, I stand corrected, my apologies.

But I'll still say the chances of the "theoretical load" of each litter being exact is extremely slim, since breedings don't produce 1000 puppies in a litter..in real life, genetics just aren't that..tidy.

You can count on the fact that a clear dog can never produce an affected puppy, and an affected dog can never produce a clear. When it comes to using carriers for breeding, you're at the mercy of the roll of the genetic dice..anything could happen. You could have all clears, you could have all carriers, you could have all affecteds..or you could have any combination of the three categories.

Very true, this is why I don't think carriers should be bred to carriers. You never know.

 

[Murreydobe]

Very true, this is why I don't think carriers should be bred to carriers. You never know.

Well..it's a difficult situation when there are so few clear dobermans. Do you restrict the genepool to only clear x clear or clear x carrier breeding and run the risk of having some WORSE health problem become a big issue?

I'd be the first to agree with you about this if dobermans had the same type of vWD as shelties or scotties, where affected status can be a death sentence. But since MOST affected dobermans never become clinically affected, the risk is probably worth it..we need more clear dogs in the breeding population, and the only way we're going to get them is by doing carrier x carrier breeding. We have to produce some affected puppies now so we can stop producing them in the future.

Not only are there more clear dobermans around now than ever before, but there are more clears that are actually viable choices. When the dna test first came out, many of the clear dogs were carrying around some baggage that no one would want...temperament issues, other far major health problems, serious structural faults. While I think many doberman breeders could probably move towards never producing another affected puppy faster than they are, progress HAS been made, things are getting better.

 

[SummerRiot]

If you breed clear X clear you'll have a HIGHER chance of CLEAR babies and essential a better breeding pool...

 

[Dekka]

Also if you breed clear to carrier enough soon your gene pool will be larger and you can then go to breeding clear to clear. Breeding carrier to carrier is silly. Even sillier than closed studbooks and breeding for looks over workability health and temperment.